Fiber reinforced composite (FRC) materials have excellent mechanical properties such as strength and rigidity while being lightweight, and therefore are widely used as aircraft members, spacecraft members, automobile members, railway car members, ship members, sports apparatus members, and computer members such as housings for laptops, and the demand is increasing year by year. Of these fields, aircraft members and spacecraft members require particularly excellent mechanical properties and heat resistance, so carbon fibers are most commonly used as the reinforcing fiber. Herein, examples of spacecraft members include members that are used in man-made satellites, rockets, and space shuttles and the like.
FRC components may be manufactured using fibers that are pre-impregnated with the matrix component, also known as prepregs. To form a composite part from the prepregs, one or more layers of prepregs are assembled within a mold and heat may be applied to cause the matrix resin to flow, enabling consolidation of the prepreg layers. The applied heat may additionally cure or polymerize the matrix components.
The consolidation of prepregs to form composites in this manner is difficult, however. Techniques have been developed to enhance removal of entrapped gases during composite fabrication, however, problems remain. Gases may be trapped from insufficient evacuation of the air before full consolidation by evacuation of the air path. Removal of these volatiles may be inhibited due to the use of the prepreg on large structures, complex geometries and layup sequences that cause parts of the prepreg to lose its connection to the outside air path. Also insufficient pressure from autoclave or vacuum bag only processing can increase the void content of the FRC components. To reduce the disassociation of these volatiles from the matrix and to decrease the growth of voids from trapped gases a reduced temperature cure can be used. This however, creates long processing times due to the slower cure time of the matrix resin at these low cure temperatures. If a matrix resin is made to cure too quickly for certain systems such as interlayer toughened systems there may not be sufficient time for the prepreg to fully consolidate.